Desulfurization of Simulated Coking Benzene on Modified Activated Clay

2012 ◽  
Vol 524-527 ◽  
pp. 876-882 ◽  
Author(s):  
Chun Guang Pan ◽  
Hong Zhu Ma
Keyword(s):  
Removal Efficiency ◽  
Atmospheric Pressure ◽  
Catalytic Properties ◽  
Temperature Programmed Desorption ◽  
Acid Strength ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Temperature Programmed

Two catalysts, SO42-/activated clay (SAC) and SO42-/Fe2O3 activated clay (SFAC) were obtained by activated clay with or without Fe2O3 loading then treated with H2SO4. The acidity of the catalysts were measured by temperature-programmed desorption of ammonia (NH3-TPD), and the results confirm that the SFAC catalyst has higher acid strength than SAC catalyst. Other techniques such as X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and energy dispersive X-ray spectroscopy (EDXS) were also employed to characterize the structure of catalysts. Its catalytic properties in desulfurization reaction from the simulated coking benzene by alkylation method was also investigated under mild conditions (353 K and atmospheric pressure), the thiophene removal efficiency can reach 42% for SAC catalyst and 99% for SFAC catalyst, respectively.

Effects of SiO2/Al2O3 Ratio on Physicochemical Properties and Catalytic Performance of the Non-Templated ZSM-5 Zeolite

2011 ◽  
Vol 197-198 ◽  
pp. 992-995
Author(s):  
Wei Qiao Liu ◽  
Wei Ning Lei ◽  
Tong Ming Shang ◽  
Zhi Gang Mou ◽  
Heng Qiang Wang ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Temperature Programmed Desorption ◽  
Catalytic Performance ◽  
Acid Sites ◽  
X Ray Diffraction ◽  
Lewis Acid Sites ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Temperature Programmed

The ZSM-5 zeolites of various SiO2/Al2O3ratios were synthesized without using any template agent. X-ray diffraction (XRD), transmission electron microscope (TEM), temperature- programmed desorption of ammonia (NH3-TPD) and Fourier transform infrared spectroscopy (FT-IR) techniques were employed to analyze the natures of the as-synthesized zeolite. The results show that the as-synthesized non-templated ZSM-5 zeolite is very pure. Meanwhile, Lewis acid sites and Bronsted acid sites are all presented in the as-synthesized non-templated HZSM-5 zeolite. The number of acid sites decreases almost linearly with the increasing of SiO2/Al2O3ratio of the zeolite. In addition, the reaction of propylene oligomerization was carried out over the as-synthesized non-templated HZSM-5 zeolite to evaluate the catalytic properties. The results show that the catalytic activity of propylene oligomerization decreases with the increasing of SiO2/Al2O3ratio.

Selective catalytic reduction of NO by Co-Mn based nanocatalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vahid Zabihi ◽  
Mohammad Hasan Eikani ◽  
Mehdi Ardjmand ◽  
Seyed Mahdi Latifi ◽  
Alireza Salehirad
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Energy Dispersive ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
Acidic Sites ◽  
Temperature Window ◽  
Temperature Programmed

Abstract One of the most significant aspects in selective catalytic reduction (SCR) of nitrogen oxides (NOx) is developing suitable catalysts by which the process occurs in a favorable way. At the present work SCR reaction by ammonia (NH3-SCR) was conducted using Co-Mn spinel and its composite with Fe-Mn spinel, as nanocatalysts. The nanocatalysts were fabricated through liquid routes and then their physicochemical properties such as phase composition, degree of agglomeration, particle size distribution, specific surface area and also surface acidic sites have been investigated by X-ray diffraction, Field Emission Scanning Electron Microscope, Energy-dispersive X-ray spectroscopy, energy dispersive spectroscopy mapping, Brunauer–Emmett–Teller, temperature-programmed reduction (H2-TPR) and temperature-programmed desorption of ammonia (NH3-TPD) analysis techniques. The catalytic activity tests in a temperature window of 150–400 °C and gas hourly space velocities of 10,000, 18,000 and 30,000 h−1 revealed that almost in all studied conditions, CoMn2O4/FeMn2O4 nanocomposite exhibited better performance in SCR reaction than CoMn2O4 spinel.

scholarly journals Adsorción del naranja de metilo en solución acuosa sobre hidróxidos dobles laminares

2015 ◽  
Vol 25 (3) ◽  
pp. 25-34 ◽  
Author(s):  
Laura Alicia Ramírez Llamas ◽  
Araceli Jacobo Azuara ◽  
J. Merced Martínez Rosales
Keyword(s):  
Methyl Orange ◽  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Temperature Programmed Desorption ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Suitable Temperature ◽  
Temperature Programmed ◽  
Double Hydroxides

In this paper, layered double hydroxides (LDH) were synthesized and characterized using techniques of Physisorption of Nitrogen, Infrared, Temperature Programmed Desorption, X-Ray Diffraction, TGA and Immersion Microcalorimetry, in order to determine the basic properties of the adsorbent. The methyl orange (MO) is used as a dye and as a result, it is frequently found in effluents from textile industries. The dye adsorption isotherms on LDH were studied as function of pH and temperature. The maximum adsorption capacity of methyl orange on LDH was carried out at pH 5, and the minimum adsorption capacity at pH 11, being 40.2 mg/g and 22.1 mg/g, respectively. Furthermore, the suitable temperature to promote the adsorption of methyl orange on LDH was at 25 °C, as at 35 °C shows a significant decrease. 

scholarly journals In-Exchanged CHA Zeolites for Selective Dehydrogenation of Ethane: Characterization and Effect of Zeolite Framework Type

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 807
Author(s):  
Zen Maeno ◽  
Xiaopeng Wu ◽  
Shunsaku Yasumura ◽  
Takashi Toyao ◽  
Yasuharu Kanda ◽  
...  
Keyword(s):  
Active Sites ◽  
Temperature Programmed Desorption ◽  
X Ray Diffraction ◽  
Zeolite Framework ◽  
X Ray ◽  
Catalytic Activities ◽  
Ethane Dehydrogenation ◽  
Temperature Programmed

In this study, the characterization of In-exchanged CHA zeolite (In-CHA (SiO2/Al2O3 = 22.3)) was conducted by in-situ X-ray diffraction (XRD) and ammonia temperature-programmed desorption (NH3-TPD). We also prepared other In-exchanged zeolites with different zeolite structures (In-MFI (SiO2/Al2O3 = 22.3), In-MOR (SiO2/Al2O3 = 20), and In-BEA (SiO2/Al2O3 = 25)) and different SiO2/Al2O3 ratios (In-CHA(Al-rich) (SiO2/Al2O3 = 13.7)). Their catalytic activities in nonoxidative ethane dehydrogenation were compared. Among the tested catalysts, In-CHA(Al-rich) provided the highest conversion. From kinetic experiments and in-situ Fourier transform infrared (FTIR) spectroscopy, [InH2]+ ions are formed regardless of SiO2/Al2O3 ratio, serving as the active sites.

scholarly journals Experimental Investigations of the Interaction of SO2 with MgO

1999 ◽  
Vol 590 ◽  
Author(s):  
Andrea Freitag ◽  
J. A. Rodriguez ◽  
J. Z. Larese
Keyword(s):  
High Resolution ◽  
Film Thickness ◽  
Room Temperature ◽  
Temperature Programmed Desorption ◽  
Experimental Investigations ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Temperature Programmed ◽  
X Ray Absorption

ABSTRACTHigh resolution adsorption isotherms, temperature programmed desorption (TPD), x-ray diffraction (XRD) and x-ray absorption near edge spectroscopy (XANES) methods were used to investigate the interaction of SO2 with high quality MgO powders. The results of these investigations indicate that when SO2 is deposited on MgO in monolayer quantities at temperatures near 100K both SO3 and SO4 species form that are not removed by simply pumping on the pre-dosed samples at room temperature. TPD and XANES studies indicate that heating of pre-dosed MgO samples to temperatures above 350 °C is required for full removal of the SO3/SO4 species. XANES measurements made as a function of film thickness indicate for coverages near monolayer completion that the SO4 species form first.

scholarly journals Promotion Effect of CaO Modification on Mesoporous Al2O3-Supported Ni Catalysts for CO2Methanation

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Wen Yang ◽  
Yanyan Feng ◽  
Wei Chu
Keyword(s):  
Surface Coverage ◽  
Temperature Programmed Desorption ◽  
Impregnation Method ◽  
Nio Nanoparticles ◽  
X Ray Diffraction ◽  
Ni Catalysts ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Supported Ni

The catalysts Ni/Al2O3and CaO modified Ni/Al2O3were prepared by impregnation method and applied for methanation of CO2. The catalysts were characterized by N2adsorption/desorption, temperature-programmed reduction of H2(H2-TPR), X-ray diffraction (XRD), and temperature-programmed desorption of CO2and H2(CO2-TPD and H2-TPD) techniques, respectively. TPR and XRD results indicated that CaO can effectively restrain the growth of NiO nanoparticles, improve the dispersion of NiO, and weaken the interaction between NiO and Al2O3. CO2-TPD and H2-TPD results suggested that CaO can change the environment surrounding of CO2and H2adsorption and thus the reactants on the Ni atoms can be activated more easily. The modified Ni/Al2O3showed better catalytic activity than pure Ni/Al2O3. Ni/CaO-Al2O3showed high CO2conversion especially at low temperatures compared to Ni/Al2O3, and the selectivity to CH4was very close to 1. The high CO2conversion over Ni/CaO-Al2O3was mainly caused by the surface coverage by CO2-derived species on CaO-Al2O3surface.

The Effect of Thermal Treatment on the Structure of Palygorskite Used for Flue Gas SO2 Removal

2011 ◽  
Vol 356-360 ◽  
pp. 698-703 ◽  
Author(s):  
Xian Long Zhang ◽  
Wei Ping Jiang ◽  
Xue Ping Wu ◽  
Bo Wen Shi ◽  
Bao Jun Yang ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Structural Properties ◽  
Flue Gas ◽  
Temperature Programmed Desorption ◽  
Flue Gas Desulfurization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Sites ◽  
Transmission Electron ◽  
Temperature Programmed

Palygorskite is widely used as industrial adsorbent and also potential for flue gas desulfurization by adsorption of SO2. The effect of thermal treatment on Palygorskite’s structural properties and its performance in SO2adsorption were investigated. The textural and structural properties of the prepared palygorskite adsorbent were characterized by X-ray diffraction, transmission electron microscopy and temperature programmed desorption. The result showed the channel of Palygorskite is partial collapsed and the structure is not changed ultimately when thermally treated below 300 °C. The structure of Palygorskite is Gradually changed when the treating temperature is higher than 300 °C and is damaged entirety till 800 °C. As a result, the adsorption capacity of SO2on Palygorskite decreased drastically. It is suggested that the presences of surface adorbed water and zeolitic water which occupy a large number of adsorption sites are disadvantage for the adsorption of SO2, and dissimilarly the presence of crystal-bonded water is favorable.

Effect of the Addition of In to Co/HMCM-49 Catalyst for the Selective Catalytic Reduction of NO Under Lean-burn Conditions

2010 ◽  
Vol 224 (06) ◽  
pp. 907-920 ◽  
Author(s):  
Fei Li ◽  
Dehai Xiao ◽  
Jing Li ◽  
Xiangguang Yang
Keyword(s):  
Selective Catalytic Reduction ◽  
Wide Temperature Range ◽  
Catalytic Reduction ◽  
Temperature Programmed Desorption ◽  
X Ray Diffraction ◽  
Lean Burn ◽  
Reduction Of No ◽  
X Ray ◽  
Scr Of No ◽  
Temperature Programmed

AbstractSelective catalytic reduction (SCR) of NO with propane using bimetals (3Co2Ce, 3Co2Sr, 3Co2Sn and 3Co2In) loaded on HMCM-49 zeolite was studied under lean-burn condition. Only 3Co2In/HMCM-49 exhibited higher deNOx activity in a wide temperature range. The catalysts were characterized by N2-adsoption, X-ray diffraction (XRD), temperature-programmed surface reactions (TPSR) and temperature-programmed desorption (TPD) of NO. TPSR and TPD results exhibited that the addition of In inhibited the oxidation ability of Co on 3Co2In/HMCM-49 catalyst, but enhanced NOx adsorption.

Sign in / Sign up

Export Citation Format

Share Document